Chemical Constituents from Mushroom Suillus luteus (Agaricomycetes) and Their Bioactivities.

Wild edible mushrooms are a huge source to discover bioactive natural products. In this work, one new polyprenylphenol derivative, termed 2-geranylgeranyl-1,4-benzenediol 1-O-acetate (1), together with eight known compounds (2-9) were isolated from wild edible mushroom Suillus luteus. The structure of new compound was elucidated by high-resolution electrospray ionization mass spectroscopy and nuclear magnetic resonance data. The structures of known compounds were elucidated by comparison of their nuclear magnetic resonance data with literature data. Compounds 1-7 exhibited significant 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity with IC50 values ranging from 1.55 ± 0.29 to 19.89 ± 2.28 µM. In addition, compounds 1-7 also showed tyrosinase inhibitory activity with IC50 values ranging from 21.97 ± 3.74 to 66.26 ± 6.85 µM.

Scopulibacillus cellulosilyticus sp. nov., a cellulose-degrading bacterium isolated from tea.

A Gram-stain positive, aerobic, non-motile, endospore-forming and rod-shaped strain (THG-NT9T) was isolated from a green tea sample. Growth occurred at 20-45 °C (optimum 28-35 °C), at pH 6.0-8.0 (optimum 7.0) and at 0-2.0% NaCl (optimum 0%). Based on 16S rRNA gene sequence analysis, the near phylogenetic neighbours of strain THG-NT9T were identified as Scopulibacillus daqui DSM 28236T (98.6%), Scopulibacillus darangshiensis DSM 19377T (97.4%), Pullulanibacillus pueri CGMCC 1.12777T (96.7%) and Pullulanibacillus camelliae CGMCC 1.15371T (96.3%). The DNA G + C content of strain THG-NT9T was determined to be 47.5 mol %. DNA-DNA hybridization values between strain THG-NT9T and S. daqui DSM 28236T, S. darangshiensis DSM 19377T, P. pueri CGMCC 1.12777T, P. camelliae CGMCC 1.15371T and Pullulanibacillus naganoensis DSM 10191T were 41.3 ± 0.1 (39.4 ± 0.4% reciprocal analysis), 39.1 ± 0.1 (37.3 ± 0.1%), 21.4 ± 0.7 (20.1 ± 0.3%), 20.7 ± 0.1 (20.1 ± 0.4%) and 12.1 ± 0.2% (8.3 ± 0.2%). The polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and three unidentified lipids. The quinone was identified as MK-7. The major fatty acids were C18:3 ω7c, iso-C15:0, iso-C16:0, iso-C17:0 and anteiso-C17:0. The cell wall type was determined to be A1γ peptidoglycan with meso-diaminopimelic acid as the diagnostic diamino acid plus alanine and glutamic acid and glucose as the cell wall sugar. On the basis of the phylogenetic analysis, chemotaxonomic data, physiological characteristics, and DNA-DNA hybridization data, strain THG-NT9T represents a novel species of the genus Scopulibacillus, for which the name Scopulibacillus cellulosilyticus sp. nov. is proposed. The type strain is THG-NT9T (= KCTC 33918T = CGMCC 1.16305T).

Sphingomonas rhizophila sp. nov., isolated from rhizosphere of Hibiscus syriacus.

A Gram-stain-negative, aerobic, non-motile, rod-shaped, catalase-positive and oxidase-positive bacteria (THG-T61T), was isolated from rhizosphere of Hibiscus syriacus. Growth occurred at 10-37 °C (optimum 25-30 °C), at pH 5.0-9.0 (optimum 7.0) and in the presence of 0-2.0 % NaCl (optimum without NaCl supplement). Based on 16S rRNA gene sequence analysis, the nearest phylogenetic neighbours of strain THG-T61T were identified as Sphingomonas ginsengisoli KCTC 12630T (97.9 %), Sphingomonas jaspsi DSM 18422T (97.8 %), Sphingomonas astaxanthinifaciens NBRC 102146T (97.4 %), Sphingomonassediminicola KCTC 12629T (97.2 %), 'Sphingomonas swuensis' KCTC 12336 (97.1 %) and Sphingomonas daechungensis KCTC 23718T (96.9 %). The isoprenoid quinone was ubiquinone-10 (Q-10). The major fatty acids were C16 : 0, C17 : 1ω6c, summed feature 4 (iso-C15 : 0 2-OH and/or C16 : 1ω7c) and summed feature 7 (C18 : 1ω7c, C18 : 1ω9t and/or C18 : 1ω12t). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, sphingoglycolipid, one unidentified lipid, one unidentified phospholipid, one unidentified glycolipid and one unidentified phosphoglycolipid. The polyamine was homospermidine. The DNA G+C content of strain THG-T61T was 65.6 mol%. The DNA-DNA relatedness values between strain THG-T61T and its closest reference strains were less than 49.2 %, which is lower than the threshold value of 70 %. Therefore, strain THG-T61T represents a novel species of the genus Sphingomonas, for which the name Sphingomonas rhizophila sp. nov. is proposed. The type strain is THG-T61T (=KACC 19189T=CCTCC AB 2016245T).

Inhibitory and Acceleratory Effects of Inonotus obliquus on Tyrosinase Activity and Melanin Formation in B16 Melanoma Cells.

The aim of the present study is to preliminarily investigate the antimelanogenesis effect of Inonotus obliquus extracts by cell-free mushroom tyrosinase assay. It was found that petroleum ether and n-butanol extracts might contain unknown potential tyrosinase inhibitors, while its ethyl acetate extract might contain some unknown accelerators. Six compounds were isolated and their structures were identified by interpretation of NMR data and nicotinic acid was first discovered in Inonotus obliquus. In cells testing, betulin and trametenolic acid decreased tyrosinase activity and melanin content, while inotodiol and lanosterol significantly increased tyrosinase activity and melanin content, showing an AC⁡50 of 9.74 and 8.43 µM, respectively. Nicotinie acid, 3ß,22,25-trihydroxy-lanosta-8-ene, had a little or no effect on tyrosinase. Betulin exhibited a mode of noncompetitive inhibition with a K I = K IS of 0.4 µM on tyrosinase activity showing an IC50 of 5.13 µM and being more effective than kojic acid (6.43 µM), and trametenolic acid exhibited a mode of mixed inhibition with a K I of 0.9 µM, K IS of 0.5 µM, and an IC50 of 7.25 µM. We proposed betulin and trametenolic acid as a new candidate of potent tyrosinase inhibitors and inotodiol and lanosterol as accelerators that could be used as therapeutic agent.

Tigliane-type diterpenoid glycosides from Euphorbia fischeriana.

Investigation of whole plants of Euphorbia fischeriana afforded three new tigliane-diterpenoid glycosides, fischerosides A-C (1-3), together with 11 known diterpenoids. Fischerosides A-C (1-3) are the first tigliane-type diterpenoid glucosides. Their structures were determined by a combination of 1D and 2D NMR, MS, and acid hydrolysis. Inhibitory activity against HIV-1 was assessed for compounds 1-5. The new compound 3 showed an EC50 value of 0.02 µM and a therapeutic index (TI) of 17.50, while prostratin (4) and 12-deoxyphorbol-13,20-diacetate (5) showed significantly greater anti-HIV-1 activity.